1. Field of the Invention
The present invention relates to a construction machine provided with a fuel supply unit for fueling a fuel tank.
2. Description of the Related Art
THE RELATED ART will be described taking a hydraulic excavator of a preferred example of the present invention as an example.
In the hydraulic excavator, as shown in FIGS. 8 and 9, an upper rotating body 2 is rotatably mounted on a crawler type lower traveling body 1 around a vertical axis. On a front part of the upper rotating body 2, is attached a working attachment 9 provided with a boom 3, an arm 4, a bucket 5, and hydraulic cylinders (boom cylinder, arm cylinder and bucket cylinder) 6, 7 and 8 for operating the boom 3, the arm 4 and the bucket 5.
A cabin 11 is installed on one of left and right sides of an upper frame 10 provided in the upper rotating body 2 (in general, on the left side seen from the rear side, hereinafter a description will be given in this example).
A side cover 12 is provided in a side surface part on the other side of the cabin 11 (on the right side), and steps 13 also serving as a front cover are provided in a part lying over a front surface part and an upper surface part. In a device chamber 14 in a front part on the right side covered by the side cover 12 and the steps 13 are installed various devices such as a valve. On the rear side of the steps 13 (in a rear part of the upper frame on the right side) is installed a fuel tank 15.
The side cover 12 is attached so as to open outward taking the rear side as a supporting point. In a state that the cover is opened, a maintenance work to the device chamber 14 is performed from the right side.
The steps 13 are formed in a stair shape and function as an up and down passage for performing maintenance from the upper surface side to an engine room (not shown) provided in a rear part of the upper rotating body 2.
In Japanese Patent Laid-Open No. 2002-266377 (hereinafter, referred to as Patent Document 1), there is a technique that a fuel supply unit having a pump and a hose is installed in order to make easier a supply work of fuel to the fuel tank 15.
In this configuration, in the vicinity of the fuel tank in the upper frame, the fuel supply unit within a case is installed.
Meanwhile, although not related to the fuel supply unit, Japanese Patent Laid-Open No. 2004-84356 (hereinafter, referred to as Patent Document 2) discloses a technique that in a construction machine having steps, a tool box is provided on a top part of the steps, and Japanese Patent Laid-Open No. 2000-45332 (hereinafter, referred to as Patent Document 3) discloses a technique that a tool box is installed on the lower side of step footboards.
However, in the technique of Patent Document 1, since there is a need for ensuring an installation space which is exclusive to the fuel supply unit on the upper frame, it is difficult to apply the technique particularly to a small sized excavator which does not have an extra space.
Meanwhile, it may be considered that the techniques related to the tool box in Patent Documents 2 and 3 are used as an installation technique for the fuel supply unit.
However, when the fuel supply unit is installed on the top part of the steps, the fuel supply unit protrudes to the upper side of the top part of the steps so that lateral visibility from an operator in the cabin is deteriorated and outer appearance is also deteriorated. Alternatively, when height is limited in order to avoid the above problem, a capability of the fuel supply unit (such as hose length) is decreased.
When the fuel supply unit is installed on the lower side of the step footboards, that is, in the device chamber 14 shown in FIG. 9, an installation space for the devices is invaded by the fuel supply unit and becomes narrower.
As a countermeasure of this point, it can be thought that height of the footboards is increased for the installation space for the fuel supply unit.
However, the steps are supported by a bracket provided in the device chamber. Therefore, when a configuration of the entire steps is changed, a configuration of the bracket also has to be changed. Consequently, conversion becomes large scale and cost is increased. When the height of the entire footboards is increased, a position of an upper end of the steps becomes higher so that the visibility from the inside of the cabin and the outer appearance are deteriorated.